HR: 1330h
AN: G22B-0312 [PDF]
TI: Multi-reference Evaluation of Uncertainty in Earth Orientation Parameter Measurements
AU: * Chin, T M
EM: mike.chin@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Gross, R S
EM: richard.s.gross@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Dickey, J O
EM: jean.o.dickey@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AB:
The earth orientation parameters including the
length of day (LOD) and polar motion (PM) are
routinely estimated by measurements from various
techniques such as the very long baseline interferometer
(VLBI), satellite laser ranging (SLR),
and global positioning system (GPS).
Objective combination of multiple data sets,
such as weighted least-squares or Bayesian statistical
(Kalman filter) estimation,
requires some quantification of the relative accuracy
of these measurements.
While statistical sampling of measurement error variances
and covariances is usually dependent on some assumed
values for the ground-truth earth orientation parameters,
we present here the evaluation of these statistics
using a technique, referred to as the "three corner hat",
that does not require the ground-truth values.
We perform such evaluation on as many as eight measurement
data sets (4 VLBI, 1 SLR, 3 GPS) as well as two combined
products that are based on daily sampling and that, when necessary,
have been interpolated to common epochs.
Daily variability of some parameters, particularly LOD, can be
high enough so that numerical interpolation error can account
for a significant fraction of the evaluated variances.
This can affect apparent error in measurement sets,
such as the VLBI data, that typically have a nominal
sampling interval longer than a day.
DE: 1239 Rotational variations
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: 2003 Fall Meeting